common/buffer.h

   1 /*
   2  *  Copyright © 2006,2007,2008 Pierre Habouzit
   3  *
   4  *  Redistribution and use in source and binary forms, with or without
   5  *  modification, are permitted provided that the following conditions
   6  *  are met:
   7  *
   8  *  1. Redistributions of source code must retain the above copyright
   9  *     notice, this list of conditions and the following disclaimer.
  10  *  2. Redistributions in binary form must reproduce the above copyright
  11  *     notice, this list of conditions and the following disclaimer in the
  12  *     documentation and/or other materials provided with the distribution.
  13  *  3. The names of its contributors may not be used to endorse or promote
  14  *     products derived from this software without specific prior written
  15  *     permission.
  16  *
  17  *  THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND ANY EXPRESS
  18  *  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  *  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20  *  DISCLAIMED.  IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
  21  *  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  *  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  *  OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  *  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  25  *  STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  26  *  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  27  *  POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 #ifndef AWESOME_COMMON_BUFFER_H
  31 #define AWESOME_COMMON_BUFFER_H
  32
  33 #include "common/util.h"
  34
  35 typedef struct buffer_t
  36 {
  37     char *s;
  38     int len, size;
  39     unsigned alloced: 1;
  40     unsigned offs   :31;
  41 } buffer_t;
  42
  43 extern char buffer_slop[1];
  44
  45 #define BUFFER_INIT (buffer_t) { .s = buffer_slop, .size = 1 }
  46
  47 #define buffer_inita(b, sz)                                                 \
  48     ({ int __sz = (sz); assert (__sz < (64 << 10));                         \
  49        buffer_init_buf((b), alloca(__sz), __sz); })
  50
  51 /** Initialize a buffer.
  52  * \param buf A buffer pointer.
  53  * \return The same buffer pointer.
  54  */
  55 static inline buffer_t *
  56 buffer_init(buffer_t *buf)
  57 {
  58     *buf = BUFFER_INIT;
  59     return buf;
  60 }
  61
  62 /** Initialize a buffer with data.
  63  * \param b The buffer to ini.
  64  * \param buf The data to set.
  65  * \param size Data size.
  66  */
  67 static inline void
  68 buffer_init_buf(buffer_t *b, void *buf, int size)
  69 {
  70     *b = (buffer_t){ .s = buf, .size = size };
  71     b->s[0] = '\0';
  72 }
  73
  74 /** Wipe a buffer.
  75  * \param buf The buffer.
  76  */
  77 static inline void
  78 buffer_wipe(buffer_t *buf)
  79 {
  80     if (buf->alloced)
  81         free(buf->s - buf->offs);
  82     buffer_init(buf);
  83 }
  84
  85 /** Get a new buffer.
  86  * \return A new allocated buffer.
  87  */
  88 static inline buffer_t *
  89 buffer_new(void)
  90 {
  91     return buffer_init(p_new(buffer_t, 1));
  92 }
  93
  94 /** Delete a buffer.
  95  * \param buf A pointer to a buffer pointer to free.
  96  */
  97 static inline void
  98 buffer_delete(buffer_t **buf)
  99 {
 100     if(*buf)
 101     {
 102         buffer_wipe(*buf);
 103         p_delete(buf);
 104     }
 105 }
 106
 107 char *buffer_detach(buffer_t *buf);
 108 void buffer_ensure(buffer_t *buf, int len);
 109
 110 /** Grow a buffer.
 111  * \param buf The buffer to grow.
 112  * \param extra The number to add to length.
 113  */
 114 static inline void
 115 buffer_grow(buffer_t *buf, int extra)
 116 {
 117     assert (extra >= 0);
 118     if (buf->len + extra > buf->size)
 119     {
 120         buffer_ensure(buf, buf->len + extra);
 121     }
 122 }
 123
 124 /** Add data in the buffer.
 125  * \param buf Buffer where to add.
 126  * \param pos Position where to add.
 127  * \param len Length.
 128  * \param data Data to add.
 129  * \param dlen Data length.
 130  */
 131 static inline void
 132 buffer_splice(buffer_t *buf, int pos, int len, const void *data, int dlen)
 133 {
 134     assert (pos >= 0 && len >= 0 && dlen >= 0);
 135
 136     if (unlikely(pos > buf->len))
 137         pos = buf->len;
 138     if (unlikely(len > buf->len - pos))
 139         len = buf->len - pos;
 140     if (pos == 0 && len + buf->offs >= dlen)
 141     {
 142         buf->offs += len - dlen;
 143         buf->s    += len - dlen;
 144         buf->size -= len - dlen;
 145         buf->len  -= len - dlen;
 146     }
 147     else if (len != dlen)
 148     {
 149         buffer_ensure(buf, buf->len + dlen - len);
 150         memmove(buf->s + pos + dlen, buf->s + pos + len, buf->len - pos - len);
 151         buf->len += dlen - len;
 152         buf->s[buf->len] = '\0';
 153     }
 154     memcpy(buf->s + pos, data, dlen);
 155 }
 156
 157 /** Add data at the end of buffer.
 158  * \param buf Buffer where to add.
 159  * \param data Data to add.
 160  * \param len Data length.
 161  */
 162 static inline void
 163 buffer_add(buffer_t *buf, const void *data, int len)
 164 {
 165     buffer_splice(buf, buf->len, 0, data, len);
 166 }
 167
 168 #define buffer_addsl(buf, data) \
 169     buffer_add(buf, data, sizeof(data) - 1);
 170
 171 /** Add a string to the and of a buffer.
 172  * \param buf The buffer where to add.
 173  * \param s The string to add.
 174  */
 175 static inline void buffer_adds(buffer_t *buf, const char *s)
 176 {
 177     buffer_splice(buf, buf->len, 0, s, a_strlen(s));
 178 }
 179
 180 /** Add a char at the end of a buffer.
 181  * \param buf The buffer where to add.
 182  * \param c The char to add.
 183  */
 184 static inline void buffer_addc(buffer_t *buf, int c)
 185 {
 186     buffer_grow(buf, 1);
 187     buf->s[buf->len++] = c;
 188     buf->s[buf->len]   = '\0';
 189 }
 190
 191 void buffer_addvf(buffer_t *buf, const char *fmt, va_list)
 192     __attribute__((format(printf, 2, 0)));
 193
 194 void buffer_addf(buffer_t *buf, const char *fmt, ...)
 195     __attribute__((format(printf, 2, 3)));
 196
 197 #endif